Add list option

This option lists enumeration identifiers, along with their string forms
for clarity's sake. This makes it much easier to blacklist things
without reading the source code.

A note about listing has been added to the Blacklisting section of the
README.

A dedicated action has been created for the list command.

README.md

@@ -55,6 +55,12 @@ You may wish to blacklist options that:
 * add Exhaustion
 * you simply don't have a good source for
 
+To get a list of identifiers, use:
+```sh
+pipenv run bone_market_solver --list
+```
+Specific enumerations may be provided to narrow what is shown.
+
 ### Configuration Files
 
 Rather than typing out every argument each time you use the solver, you may provide a file path (prefixed with "@") to the CLI.

bonemarketsolver/__main__.py

@@ -4,6 +4,7 @@ import curses
 from .objects.blacklistaction import BlacklistAction
 from .objects.bonemarketargumentparser import BoneMarketArgumentParser
 from .objects.enumaction import EnumAction
+from .objects.listaction import ListAction
 from .solve import *
 
 parser = BoneMarketArgumentParser(
@@ -13,6 +14,16 @@ parser = BoneMarketArgumentParser(
         argument_default=argparse.SUPPRESS,
         )
 
+parser.add_argument(
+        "-l", "--list",
+        action=ListAction,
+        default=ListAction.list_options,
+        choices=ListAction.list_options,
+        nargs=argparse.ZERO_OR_MORE,
+        help="list specified enumerations and their names and exit",
+        dest=argparse.SUPPRESS
+        )
+
 
 world_qualities = parser.add_argument_group(
         "world qualities",

bonemarketsolver/objects/listaction.py

@@ -0,0 +1,53 @@
+__all__ = ['ListAction']
+__author__ = "Jeremy Saklad"
+
+import argparse
+from functools import reduce
+
+from ..data.adjustments import Adjustment
+from ..data.appendages import Appendage
+from ..data.buyers import Buyer
+from ..data.declarations import Declaration
+from ..data.embellishments import Embellishment
+from ..data.skulls import Skull
+from ..data.torsos import Torso
+
+class ListAction(argparse.Action):
+    """Lists enumerations referenced by provided strings then exits"""
+
+    list_options = [enum.__name__.lower() for enum in [
+                Torso,
+                Skull,
+                Appendage,
+                Adjustment,
+                Declaration,
+                Embellishment,
+                Buyer,
+            ]]
+
+    def __init__(self, **kwargs):
+        nargs = kwargs.get('nargs')
+        default = kwargs.get('default')
+
+        super(ListAction, self).__init__(**kwargs)
+
+        self._nargs = nargs
+        self._default = default
+
+    @staticmethod
+    def printable_list(enum):
+        def printable_item(member):
+            return f"\n\t{enum.__name__}.{member.name}:\n\t\t{member}"
+
+        return "{}:{}".format(enum.__name__, str().join([printable_item(member) for member in enum]))
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        # Check whether this is a single value or a list of them
+        if self._nargs is None or self._nargs == argparse.OPTIONAL:
+            # Convert value into an Enum type and print
+            print(self.printable_list(globals()[values.capitalize()]))
+        else:
+            # Convert values back into Enum types and print
+            print(*[self.printable_list(globals()[value.capitalize()]) for value in (values if values else self._default)], sep="\n\n")
+
+        parser.exit()